You should be able to do it. First, do you know whether the extractor rod is left or right hand threads? (Depends on the age of the gun.)
Remove the cylinder and crane by removing the front sideplate screw and then pulling the cylinder and crane assembly forward. Leave the crane with the cylinder for support. Now place three empty cartridge cases in alternate chambers. Using copper jaws, or a couple of pieces of copper, clamp the front of the extractor rod in a vise. Don't use pliers; they will slip.
If there is a deep circular cut behind the knurled portion of the extractor rod, the threads are left hand, so turn the cylinder clockwise to unscrew the ejector rod. (If there is no cut, unscrew to the left (CCW) in the normal way.)
The extractor rod screws into the extractor, so with it unscrewed, the extractor will pull right out. The new one should fit right in provided you have the correct part. Make sure you get the slot in the rod on the little stud in the cylinder and the pins line up with the holes (they should). Also, make sure the ejector doesn't interfere with loading or unloading. Rarely, a small file may be needed to remove burrs.
Tighten down the extractor rod in the opposite direction to removal. With the rod screwed back in, try everything to make sure the cylinder opens and closes OK and the extractor rod moves freely. Then remove the extractor rod again, put a dab of blue Loctite on the threads and reassemble.
Jim
